Backgrounder

Use of Radio Telemetry for the monitoring of animals started for the first time in India on crocodiles in the year 1983 at the Centre for Crocodile Breeding Management and Training (CCBMT) , Hyderabad (erstwhile centre of Wildlife Institute of India. Subsequently, this technology has increasingly being used to understand the movement of wild animals and their use pattern of the habitat as indicated below:

(1) Wildlife Institute of India (WII), in association with Gujarat Forest Department has been monitoring movement of lions by fitting radio collars with VHF (very high frequency) GPS and satellite uplink facility. The use of this technology helped in identifying the corridors connecting Gir National Park with adjoining sanctuaries and forest areas. Based on this study, the areas around the Gir National Park have been identified by the Gujarat Forest Department and these are being managed as part of the Greater Gir landscape.

(2) Under the aegis of National Tiger Conservation Authority (NTCA), MoEF and in association with State governments of Rajasthan, Madhya Pradesh, WII has used radio collars on tigers which have been re-introduced in Sariska Tiger Reserve and Panna Tiger Reserve respectively to keep a track of their movement and subsequent adjustment to the new habitats.

(3) WII and Madhya Pradehs Forest Department are currently engagd in monitoring of Garu in Bandhavgarh Tiger Reserve which have been brought from Kanha Tiger Reserve by using VHF and satellite collars.

(4) With the funding support from Director Genetal, Hydrocarbons (DGH), Ministry of Petroleum, WII fixed Platform Transmitted Terminals (PTTs) on more than 30 olive ridley turtles to monitor their movement and use of marine area off the coast of Orissa. This study has been undertaken to provide information on use of offshore areas by this endangered species (spatial and temporal) for identifying window for oil explorations.

In addition to above , radio telemetry studies have also been done in past on elephants, birds (bar headed geese) and reptiles (king cobra).

(6) A pilot projects on e-surveillance in Corbett Tiger Reserve under the aegis of NTCA has been initiated. This technology will not only provides information on the movement of the animals but also will keep watch on poaching and other undesirable activities in the park.

(7) WII in association with the Gujarat Institute of Information Technology, IIT, Delhi and Indian Institute of Information Technology, Allahabad is working on a project for use of sensor network technology for monitoring of various species of wild animals.

Radio collar and its usage

A radio collar is a wide band of machine – belting fitted with a small radio transmitter and battery. The transmitter emits a signal at a specific frequency that can be tracked from up to 5 kms away. When trying to locate a particular collared animal, the appropriate frequency is dialed, and signal is detected using a directional antenna, usually mounted on top of a vehicle. Once detected, the signal provides the direction lead to the animal.

Since Radio collars are used because wild animals are elusive, usually hidden in dense vegetation, and range over large distances in rough terrain, it is difficult to track them visually. Radio telemetry is used to track such animals, and understand their movement patterns.

A veterinarian uses a dart gun to inject the animal with chemical substances called sedatives or tranquilisers, which immobilise the animal. Once the animal is immobilized, it is fitted with a radio collar. The animal is then injected with an antidote, and it revives soon.

The animals take some time to get accustomed to the collar, but soon begin to ignore it . The collar is appropriately fitted to prevent getting stuck in vegetation, while being loose enough to be comfortable to the animal. There is no evidence to indicate any long-term negative effect of the collars on animals.

Types of Radio collars

There are two types of collars in use: Very High Frequency (VHF) ADN Global Positioning System (GPS).VHF collars are the traditional radio collars, which send out a steady signal which are detected with an antenna and receiver, carried on foot, or mounted on a vehicle or aircraft . A VHF collar lasts at least three years on an animal, after which a new one with fresh batteries is fitted.

GPS collars are more sophisticated and incorporate a GPS receiver which s set to take  position fixes at regular intervals, which are stored in the collar and then remotely downloaded to a computer via a Ultra High Frequency (UHF) radio link. The animal does not need to be recaptured in order to get the data. It helps in mapping an animal’s movement round the clock, allowing studies of home range, movements according to habitat types, human activity or wildlife concentrations, etc. GPS collars are much more expensive as compared to VHF collars, and consume more battery power, because of which they need to be replaced within a year. A satellite GPS collar is currently being experimented, which is costlier but enables information without the need of a receiver.

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KP